<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <style>
      #cdr {
        width: 0px;
        height: 0px;
        border-right: 60px solid transparent;
        border-top: 60px solid red;
        border-left: 60px solid red;
        border-bottom: 60px solid red;
        border-top-left-radius: 60px;
        border-top-right-radius: 60px;
        border-bottom-left-radius: 60px;
        border-bottom-right-radius: 60px;
      }
    </style>
  </head>
  <body>
    <p>正方形 右边框透明 + 每一个border-radius设置度数</p>
    <div id="cdr"></div>
  </body>
</html>
